MARATHON PIPE LINE LLC

Incident Narrative

ON MAY 24, 2022 AT 07:00 MT, THE MPL SAN ANTONIO PIPELINE OPERATIONS CENTER (OC) RECEIVED A CALL FROM A 3RD PARTY OPERATOR INDICATING THEY HAD OBSERVED CRUDE OIL ON THE GROUND (ENTIRELY CONTAINED WITHIN THE STATION BOUNDARIES), SINCE THE CRUDE OIL WAS NEAR MPL'S PUMP UNIT #1, THEY HAD REQUESTED TO SHUT DOWN THE PUMPING UNIT. THE PUMP UNIT WAS SHUT DOWN AT 07:03 MT. LOCAL FIELD OPERATIONS IMMEDIATELY RESPONDED, ARRIVING ON SITE AT 07:25 MT. APPROXIMATELY 1.8 BARRELS OF CRUDE WAS RELEASED. THERE WERE NO INJURIES, FIRES, EXPLOSIONS, OR IMPACTS TO WILDLIFE OR WATER. THE LEAK WAS FOUND TO HAVE ORIGINATED ON A 1-INCH NIPPLE THAT IS ROUTED TO THE DISCHARGE PRESSURE TRANSMITTER. NDT TEST RESULTS INDICATED THERE WAS A 180 DEGREE CRACK ALONG THE THREADS OF THE NIPPLE. THE CRACK ON THE FAILED NIPPLE WAS DETERMINED TO HAVE OCCURRED AS THE RESULT OF EXCESS VIBRATIONS RESULTING FROM RECENT INCREASES IN PUMP SPEED. NDT WAS ALSO PERFORMED ON THE REPLACEMENT NIPPLE PRIOR TO IT BEING INSTALLED TO ENSURE NO CRACKS WERE PRESENT. PRIOR TO RESTARTING THE SYSTEM ON MAY 24, 2022 AT 19:46 MT, REMEDIAL ACTIONS WERE TAKEN TO PREVENT RECURRENCE INCLUDING LOWERING THE SPEED OF THE PUMPS AND INSTALLING HIGH PRESSURE STAINLESS STEEL FLEXIBLE HOSES TO REPLACE THE STAINLESS STEEL TUBING THAT WAS IN-PLACE AT THE TIME THE EVENT OCCURRED. MPL IS CONTINUING TO EVALUATE ADDITIONAL ACTIONS TO FURTHER REDUCE VIBRATIONS. UPDATE AUGUST 9, 2022 - THIS SUPPLEMENTAL REPORT ADJUSTS THE SUB-CAUSE TO THREADED CONNECTION/PIPE NIPPLE. THE INVESTIGATION HAS BEEN COMPLETED WITH NO FURTHER UPDATES.